fix couple bugs in ARP and add benchmarks

arp/handler.go

@@ -191,24 +191,25 @@ func (h *Handler) Encapsulate(carrierData []byte, offsetToIP, offsetToFrame int)
 		return n, nil
 	}
 	for i := range h.queries {
-		if !h.queries[i].querysent {
+		if h.queries[i].isInvalid() || h.queries[i].querysent {
-			h.queries[i].querysent = true
+			continue
-			afrm, _ := NewFrame(b)
-			afrm.SetHardware(h.htype, uint8(len(h.ourHWAddr)))
-			afrm.SetProtocol(h.protoType, uint8(len(h.ourProtoAddr)))
-			afrm.SetOperation(OpRequest)
-			hwSender, protoSender := afrm.Sender()
-			copy(hwSender, h.ourHWAddr)
-			copy(protoSender, h.ourProtoAddr)
-			hwTarget, protoTarget := afrm.Target()
-			copy(protoTarget, h.queries[i].protoaddr)
-			for j := range hwTarget {
-				hwTarget[j] = 0
-			}
-			broadcast := ethernet.BroadcastAddr()
-			trySetEthernetDst(carrierData[:offsetToFrame], broadcast[:])
-			return n, nil
 		}
+		h.queries[i].querysent = true
+		afrm, _ := NewFrame(b)
+		afrm.SetHardware(h.htype, uint8(len(h.ourHWAddr)))
+		afrm.SetProtocol(h.protoType, uint8(len(h.ourProtoAddr)))
+		afrm.SetOperation(OpRequest)
+		hwSender, protoSender := afrm.Sender()
+		copy(hwSender, h.ourHWAddr)
+		copy(protoSender, h.ourProtoAddr)
+		hwTarget, protoTarget := afrm.Target()
+		copy(protoTarget, h.queries[i].protoaddr)
+		for j := range hwTarget {
+			hwTarget[j] = 0
+		}
+		broadcast := ethernet.BroadcastAddr()
+		trySetEthernetDst(carrierData[:offsetToFrame], broadcast[:])
+		return n, nil
 	}
 	return 0, nil
 }

x/xnet/stack-async.go

@@ -450,6 +450,17 @@ func (s *StackAsync) ResultResolveHardwareAddress6(ip netip.Addr) (hw [6]byte, e
 	return [6]byte(hwslice), nil
 }
 
+// DiscardResolveHardwareAddress6 discards a pending ARP query for the given IP address.
+func (s *StackAsync) DiscardResolveHardwareAddress6(ip netip.Addr) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !ip.Is4() {
+		return errors.New("unsupported or invalid IP address")
+	}
+	addr := ip.As4()
+	return s.arp.DiscardQuery(addr[:])
+}
+
 type DHCPResults struct {
 	DNSServers    []netip.Addr
 	Router        netip.Addr

x/xnet/xnet_bench_test.go

@@ -0,0 +1,173 @@
+package xnet
+
+import (
+	"net/netip"
+	"testing"
+
+	"github.com/soypat/lneto/tcp"
+)
+
+func BenchmarkARPExchange(b *testing.B) {
+	const MTU = 1500
+	c1, c2 := new(StackAsync), new(StackAsync)
+	queryAddr := netip.AddrFrom4([4]byte{192, 168, 1, 2})
+
+	err := c1.Reset(StackConfig{
+		Hostname:        "C1",
+		RandSeed:        1,
+		StaticAddress:   netip.AddrFrom4([4]byte{192, 168, 1, 1}),
+		HardwareAddress: [6]byte{0xde, 0xad, 0xbe, 0xef, 0x00, 0x00},
+		MTU:             MTU,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	err = c2.Reset(StackConfig{
+		Hostname:        "C2",
+		RandSeed:        2,
+		StaticAddress:   queryAddr,
+		HardwareAddress: [6]byte{0xc0, 0xff, 0xee, 0xc0, 0xff, 0xee},
+		MTU:             MTU,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	// Set gateways so ethernet frames are properly addressed.
+	c1.SetGateway6(c2.HardwareAddress())
+	c2.SetGateway6(c1.HardwareAddress())
+
+	var buf [MTU]byte
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		err = c1.StartResolveHardwareAddress6(queryAddr)
+		if err != nil {
+			b.Fatal(err)
+		}
+		n, err := c1.Encapsulate(buf[:], -1, 0) // Send Request.
+		if err != nil {
+			b.Fatal(err)
+		} else if n == 0 {
+			b.Fatal("expected send of data after first query")
+		}
+		err = c2.Demux(buf[:n], 0) // Receive request.
+		if err != nil {
+			b.Fatal(err)
+		}
+		n, err = c2.Encapsulate(buf[:], -1, 0) // Send response.
+		if err != nil {
+			b.Fatal(err)
+		} else if n == 0 {
+			b.Fatal("got no response to request")
+		}
+		err = c1.Demux(buf[:n], 0) // Receive response.
+		if err != nil {
+			b.Fatal(err)
+		}
+		_, err = c1.ResultResolveHardwareAddress6(queryAddr)
+		if err != nil {
+			b.Fatal("expected query result:", err)
+		}
+		// Discard query for next iteration.
+		c1.DiscardResolveHardwareAddress6(queryAddr)
+	}
+}
+
+func BenchmarkTCPHandshake(b *testing.B) {
+	const MTU = 1500
+	const svPort = 8080
+	client, sv := new(StackAsync), new(StackAsync)
+	clconn, svconn := new(tcp.Conn), new(tcp.Conn)
+
+	err := sv.Reset(StackConfig{
+		Hostname:        "Server",
+		RandSeed:        1,
+		StaticAddress:   netip.AddrFrom4([4]byte{10, 0, 0, 1}),
+		MaxTCPConns:     1,
+		HardwareAddress: [6]byte{0xbe, 0xef, 0, 0, 0, 1},
+		MTU:             MTU,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	err = client.Reset(StackConfig{
+		Hostname:        "Client",
+		RandSeed:        2,
+		StaticAddress:   netip.AddrFrom4([4]byte{10, 0, 0, 2}),
+		MaxTCPConns:     1,
+		HardwareAddress: [6]byte{0xbe, 0xef, 0, 0, 0, 2},
+		MTU:             MTU,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	sv.SetGateway6(client.HardwareAddress())
+	client.SetGateway6(sv.HardwareAddress())
+
+	buf := make([]byte, MTU*4)
+	err = clconn.Configure(tcp.ConnConfig{
+		RxBuf:             buf[:MTU],
+		TxBuf:             buf[MTU : MTU*2],
+		TxPacketQueueSize: 4,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+	err = svconn.Configure(tcp.ConnConfig{
+		RxBuf:             buf[2*MTU : 3*MTU],
+		TxBuf:             buf[3*MTU : 4*MTU],
+		TxPacketQueueSize: 4,
+	})
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	var pktbuf [MTU]byte
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		// Setup connections.
+		err = sv.ListenTCP(svconn, svPort)
+		if err != nil {
+			b.Fatal(err)
+		}
+		err = client.DialTCP(clconn, 1337, netip.AddrPortFrom(sv.Addr(), svPort))
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		// SYN from client.
+		n, err := client.Encapsulate(pktbuf[:], -1, 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+		err = sv.Demux(pktbuf[:n], 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		// SYN-ACK from server.
+		n, err = sv.Encapsulate(pktbuf[:], -1, 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+		err = client.Demux(pktbuf[:n], 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		// ACK from client.
+		n, err = client.Encapsulate(pktbuf[:], -1, 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+		err = sv.Demux(pktbuf[:n], 0)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		// Abort connections for next iteration.
+		clconn.Abort()
+		svconn.Abort()
+	}
+}